From 7359393f3c19c9351e81345ef29f4f47229a6416 Mon Sep 17 00:00:00 2001 From: Julian Wiedmann Date: Wed, 18 Dec 2019 17:34:43 +0100 Subject: s390/qeth: wake up all waiters from qeth_irq() card->wait_q is shared by different users, for different wake-up conditions. qeth_irq() can potentially trigger multiple of these conditions: 1) A change to channel->irq_pending, which qeth_send_control_data() is waiting for. 2) A change to card->state, which qeth_clear_channel() and qeth_halt_channel() are waiting for. As qeth_irq() does only a single wake_up(), we might miss to wake up a second eligible waiter. Luckily all waiters are guarded with a timeout, so this situation should recover on its own eventually. To make things work robustly, add an additional wake_up() for changes to channel->state. And extract a helper that updates channel->irq_pending along with the needed wake_up(). Signed-off-by: Julian Wiedmann Signed-off-by: David S. Miller --- drivers/s390/net/qeth_core.h | 7 +++++++ drivers/s390/net/qeth_core_main.c | 27 +++++++++++---------------- 2 files changed, 18 insertions(+), 16 deletions(-) (limited to 'drivers/s390') diff --git a/drivers/s390/net/qeth_core.h b/drivers/s390/net/qeth_core.h index a23875a4fa2b..b54ef12840a2 100644 --- a/drivers/s390/net/qeth_core.h +++ b/drivers/s390/net/qeth_core.h @@ -862,6 +862,13 @@ static inline bool qeth_card_hw_is_reachable(struct qeth_card *card) return card->state == CARD_STATE_SOFTSETUP; } +static inline void qeth_unlock_channel(struct qeth_card *card, + struct qeth_channel *channel) +{ + atomic_set(&channel->irq_pending, 0); + wake_up(&card->wait_q); +} + struct qeth_trap_id { __u16 lparnr; char vmname[8]; diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c index 3d2374801308..38f3ed7567bc 100644 --- a/drivers/s390/net/qeth_core_main.c +++ b/drivers/s390/net/qeth_core_main.c @@ -520,11 +520,10 @@ static int __qeth_issue_next_read(struct qeth_card *card) } else { QETH_DBF_MESSAGE(2, "error %i on device %x when starting next read ccw!\n", rc, CARD_DEVID(card)); - atomic_set(&channel->irq_pending, 0); + qeth_unlock_channel(card, channel); qeth_put_cmd(iob); card->read_or_write_problem = 1; qeth_schedule_recovery(card); - wake_up(&card->wait_q); } return rc; } @@ -1001,24 +1000,25 @@ static void qeth_irq(struct ccw_device *cdev, unsigned long intparm, } channel->active_cmd = NULL; + qeth_unlock_channel(card, channel); rc = qeth_check_irb_error(card, cdev, irb); if (rc) { /* IO was terminated, free its resources. */ if (iob) qeth_cancel_cmd(iob, rc); - atomic_set(&channel->irq_pending, 0); - wake_up(&card->wait_q); return; } - atomic_set(&channel->irq_pending, 0); - - if (irb->scsw.cmd.fctl & (SCSW_FCTL_CLEAR_FUNC)) + if (irb->scsw.cmd.fctl & SCSW_FCTL_CLEAR_FUNC) { channel->state = CH_STATE_STOPPED; + wake_up(&card->wait_q); + } - if (irb->scsw.cmd.fctl & (SCSW_FCTL_HALT_FUNC)) + if (irb->scsw.cmd.fctl & SCSW_FCTL_HALT_FUNC) { channel->state = CH_STATE_HALTED; + wake_up(&card->wait_q); + } if (iob && (irb->scsw.cmd.fctl & (SCSW_FCTL_CLEAR_FUNC | SCSW_FCTL_HALT_FUNC))) { @@ -1052,7 +1052,7 @@ static void qeth_irq(struct ccw_device *cdev, unsigned long intparm, qeth_cancel_cmd(iob, rc); qeth_clear_ipacmd_list(card); qeth_schedule_recovery(card); - goto out; + return; } } @@ -1060,16 +1060,12 @@ static void qeth_irq(struct ccw_device *cdev, unsigned long intparm, /* sanity check: */ if (irb->scsw.cmd.count > iob->length) { qeth_cancel_cmd(iob, -EIO); - goto out; + return; } if (iob->callback) iob->callback(card, iob, iob->length - irb->scsw.cmd.count); } - -out: - wake_up(&card->wait_q); - return; } static void qeth_notify_skbs(struct qeth_qdio_out_q *q, @@ -1780,8 +1776,7 @@ static int qeth_send_control_data(struct qeth_card *card, QETH_CARD_TEXT_(card, 2, " err%d", rc); qeth_dequeue_cmd(card, iob); qeth_put_cmd(iob); - atomic_set(&channel->irq_pending, 0); - wake_up(&card->wait_q); + qeth_unlock_channel(card, channel); goto out; } -- cgit v1.2.3-59-g8ed1b